MoS2/porous carbon nanofiber heterostructures for efficient evaporation-driven generators.

Evaporation power generators (EPGs) based on natural water evaporation can directly convert heat energy from the surrounding environment into electrical energy. Nevertheless, the commercialization of EPGs faces challenges due to the low charge generation and transport efficiency of single material systems, leading to unsatisfactory open-circuit voltages and short-circuit currents. Here, we systematically prepared molybdenum sulfide (MoS₂)/porous carbon nanofiber (PCNF) heterogeneous systems by electrospinning and hydrothermal methods. Electron microscope measurements have confirmed the uniform coating of high-crystalline quality MoS₂nanosheets on PCNF fabrics, and the uneven concave-convex surface increased the specific surface area. MoS₂covered PCNF fabrics retained excellent hydrophilicity, which was suitable for absorbing water and keeping the surface wet during long-term evaporation. Moreover, layered MoS₂with rich surface charge improved the charge transfer of the MoS₂/PCNF fabrics. As a result, the open-circuit voltage and short-circuit current of the EPGs fabricated with MoS₂/PCNF fabrics were enhanced to 0.25 V and 75μA, respectively, in comparison to those based on PCNF fabrics, which demonstrated that the MoS₂coatings improved the interaction area with water and the charge transfer effect of the EPGs. This heterogeneous combination strategy provides ideas for the preparation of high-performance EPG materials.